Process for securing metals from their compounds.



WjLbrz/esses:

V. M. WEAVER.

PROCESS FOR SECURING MEIALS FROM THEIR COMPOUND S. APPLICATION min um.II. l9l5.

1 ,297,94;6. Patented Mar. 18, 1919.

4 SHEETS-SHUT I.

CONDENSER B igi-j ifji i V. M WEAVER. PROCESS FOR SECURING METALS FROMTHEIR COMPOUNDS.

APPLICATHJN FILED JAN. H. l9l5.

Patented Mar. 18, 1919.

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MPOUNDS.

Patented Mar. 18, 1919.

4 SHEETS-SHEET 3- Witnessesfzzzzezzzor mm d flm' r Vjcforff Weaveromeys.

V. M. WEAVER.

PROCESS FOR SECURING METALS FROM THEIR COMPOUNDS.

APPLICATION FILED JAN.1I. IBIS.

1,297,946. Patented Mar. 18,1919.

yo r T Witnessesfnven for 22211444 W. kit-for}! IVeaver Wfi Z/M' WW WUNITED STATES PATENT OFFICE.

VICTOR M. WEAVER, OI HARRISBURG, PENNSYLVANIA, ASSIGNOR 'IO WEAVERCOMPANY, A CORPORATION OF WISCONSIN.

PROCESS FOR SECURING METALS FROM THEIR COMPOUNDS.

Original application filed August 22, 1914, Serial No. 858,001.

Specification of Letters Patent.

Patented Mar. 18, 1919.

Divided and this application filed January 11, 1915. Serial No. 1,559.

To all whom it may concern:

Be it known that I, VICTOR M. WEAVER, a citizen of the United States,residing at Harrisburg, in the county of Dauphin and State ofPennsylvania, have invented a certain new and useful Improvement inProcesses for'Securing Metals from Their Com pounds, of which thefollowing is afull, clear, concise, and exact description, referencebeing had to the accompanying drawingz, forming a part of thisspecification.

y invention relates to a process for securing metals from theircompounds. While it will appear to those skilled in the art that myinvention may be employed in the treatment of any substances having theproper chemicahand physical characteristics, my invention is concernedarticularly with the securing of aluminum rom aluminum chlorid, aspointed out in the more specific of the appended claims.

This application is divisional from the application which resulted in myUnited States Letters Patent N 0. 1,238,604, which issued August 28,1917, and which is concerned with a process for winning metals andwhich, in its more specific aspects, relates to the treatment of clay inorder to secure the aluminum and the silicon therefrom.

The claims in the parent patent are drawn toward the process as a whole,that is, the complete process, beginning with clay and the properreagents, and ending with the recovery of the aluminum and silicon intheir elementary state.

The present application has to do with the securing of the aluminum fromthe aluminum chlorid, all in a new and advantageous manner.

In order to instruct those skilled in the art I shall now proceed with aspecific description of my invention as embodied in tion of the kaolin,

aluminum chlorid thus produced, the next step, so far as this particularpart of the process is concerned, is to secure the aluminum therefromand this I carry out by electrolysis under certain conditions andrestrictions calculated to effect an advantageous and continuousprocess. I charge the aluminum chlorid into an electrolyzing vat,preferably containing melted sodium chlorid, and the consequentelectrolysis separates the aluminum from the chlorin, so'that the formermay be tapped away from the sodium chlorid, while the latter may beconducted to a storage tank for further use. It is important in thisconnection that in carrying out my process I keep the electrolytic vatsaturated by steady, regulated additions of aluminum chlorid, and thisproves to be a feature of distinct advantage and paramount importance.

y invention will be stood by reference to drawings, in which:

Figure 1 is a more or less diagrammatic representation of the entiresystem of apparatus.

Fig. 2 is a sectional view, taken on a horizontal plane, of theelectrolyzing vat.

Figs. 3 and 4 are other sectional views.

Referring first to Fig. 1, it will be seen that the chlorinizin furnaceis shown at 9. The details of this irnace are unimportant in connectionwith the present application and it suflices to say that a charge isintroduced into the chlorinizing furnace, which is preferably heated byelectrical means. A pipe 30, which comes from a storage tank 31, is ledinto the chlorinizin furnace, as indicated in the drawing, and in thisway more readily underthe accompanying -the charge in the furnace istreated with chlorin gas from the storage tank 31, the connection beingcontrolled by a valve 32. Assumin that the charge in the furnace is ofone o the hi her grades of clay, such as kaolin, I treat this chargewith the chlorin gas in the presence of carbon. With the currentproperly applied to the furnace electrodes, the activity of the chloringas and the heat immediately effects the disintegrathe formationofaluminum chlorid and silicon tetrachlorid, and, by the combination ofthe carbon and the oxygen liberated from the kaolin, the formation ofcarbon monoxid.

The three gases thus formed naturally side header 51 and being providedwith arise and pass out of the chlorinizing furscrapers 52, 52. Insteadof being supplied nace 9 and are conducted to a condenser 33. with merecold water, however, the cooling This condenser is in the form of adouble pipes are supplied with a freezing mixclosed chamber providingthe compartment ture of ice water and salt, and the tempera- 34 and thecompartment 35, separated by a ture in the condenser element 35 isthereartition 36. The compartment 34 is profore considerably lower thanthe temperavided with a system of cooling pipes 37, 37, ture in thecondenser element 34. The which extend downwardly through and lowertemperature is s'uilicient to condense from the top of the chamber andwhich are the silicon tetrachlorid, which comes down distributedthroughout the entire space of as a colorless liquid, except for anyimthis particular compartment in order to get purities which maydiscolor it. This liquid a complete temperature control. The pipes silicn tetrachlorid passes down the slop- 37 37 are joined at the upper end,outside lng bottom of the condenser element 35 and of the chamber, bymeans of the header ipe passes through the outlet 55, controlled by 38,and circulation is ecured in any 19- the valve 56, which leads t0 thetank 57. sirable manner. In this particular con- The tank 57 has anoutlet pipe 57 denser element the system of pipes is con- The carbonmonoxid passes out of the nectedto a cold water suppl and therecondenser, element 35 through a pipe 59, sult is that as the threegasesw ich have been past a valve 60, into a closed gas pump 61,referred to enter and pass through the comand is then carried to ascrubber 62 by partment 34 the aluminum chlorid gas, means of a pipe 63,this scrubber being in which condenses at a higher temperature the formof a tank containing lime water than the silicon tetrachlorid gas, isconand having an outlet pipe 63 leading theredensed and deposits itselfas a white powfrom. This outlet pipe is provided with a der upon thepipes 37, 37 valve 64 and leads to a telescoping gas tank Since thetemperature which is produced 65, so that ressure may be kept upon theby the circulation of mere cold Water in carbon monoxid which finds itsway to this the cooling pipes 37, 37 is not sufiiciently tank, and sothat the carbon monoxid may low to condense silicon tetrachlorid, thisbe fed by way of a pipe 66 to any number gas, together with the carbonmonoxid, of burners .67, 68 and 69,- which are used for passes 'on tothe next compartment 35 of heating purposes in certain other steps ofthe condenser. Thus the first condenser the process which willhereinafter be reelement 34 is devoted to the condensation ferred to.

of the aluminum chlorid, and the white Returning now to the aluminumchlorid powder to which it is reduced is removed which has beendeposited in the form of a from the pipes upon which it is depositedpowder in the tank 45 (this powder being by means of the scrapers 39,39. The powwhite unless discolored by impurities) it will der is thusthrown down on the conveyer be noted that I have placed the burner 67 42and carried to a tank 45, the connection under this tank, and I maymention here to which is controlled by a valve 46. It that I surroundthe tank with a suitable will be seen that this tank is connected byfire wall so that I can subject the tank to a means of a pipe 47 with acompressed air high degree of heat. \Vith the valve 46 tank 48, which isfedthrough the air-comclosed, the material in the tank 45 can be ressor49. It is important, as before iudiplaced under high pressure from thetank cated, that the system be a closed system and 48, and this ressure,together with the heat that various actions Ire carried on under fromthe car on monoxid burner, melts the pressure, and I speak of itparticularly at aluminum chlorid, after which step the aluthis timebecause of the fact that the alumiminum chlorid is much more stable andnum chlorid to which I have 'ust referred is much more easily handled,due to its physiextremely deliquescent and must be kept cal condition,and desirably so in view of the free from moisture in order to avoidde-, steps which are to follow and which will composition, and theformation of hydropresently be described. I desire to state, chloricacid. When the system is closed, however, that it is entirely feasibleto conhowever, such a result is not possible, and duct the aluminumchlorid to the farther the inclosure is effective in condensing andparts of the system in its dry, infused state, keeping condensed thisvolatile substance. and therefore do not wish to be limited to Leavingthe aluminum chlorid, which has the inclusion of this step of meltingthe been deposited in the tank 45, for the presaluminum chlorid.

cut, I shall follow the course of the silicon A pipe 70 leads from thetank 45 to a valve tetrachlorid gas and the carbon monoxid 71, which inturn is connected with a pipe through the second element of the con- 72leading into a furnace, preferably of denser. The condenser element 35is prothe Rodenhauser three-phase type. This vided with a system ofcooling pipes 50 furnace comprises a heavy outer housing like the pipes37 these pipes having the outwhich is provided with a round bottom 74mounted in a correspondingly shaped base 75, the idea being that whenthe connecting pipes are temporarily detached, the furnace can be tiltedin order to tap ofi' molten metal, as will be pointed out a littlelater. The lining of the furnace provides a cavity for the molten metalwhich is formed between and around tubular casing parts within which themagnetic circuit frame and the primary coils are disposed. The detailsof this furnace do not constitute part of my present invention, but Irefer to them because it is a type of furnace well adapted for use aspart of my system. It will be seen that when the valve 71 is opened theliquid aluminum chlorid is conducted to the working chamber of theRodenhauser furnace. The reason for this step in the process is asfollows:

In the first condensation of the aluminum chlorid in the condenserelement 34, there are likely to be impurities, principally iron, and itis the object of the step in the process now under description toeliminate this iron and to secure pure aluminum chlorid. Therefore,preliminarily, the Rodenhauser furnace is charged with aluminum, and themolten bath, as illustrated, is formed when as before stated, the valve71 is opened and the liquid aluminum chlorid is fed into this bath ofmolten aluminum near the bottom thereof, the aluminum chlorid isimmediately reconverted into a gas due to the release of pressure andheat of bath, and passes up through the molten aluminum. Due to thegreater afiinity of the chlorid for the aluminum than for the iron, orother impurity for that matter, the chlorin releases the iron and takeson the proper share of aluminum. The result is that the refined aluminumchlorid will leave the bath of aluminum and will pass out of the furnacethrough the pipe 81. It will be noted that the pipe 81 divides into thepipes 82 and 83, which are provided with valves 81 and 85, respectively.

If the refined aluminum chlorid is to be further purified, the valve 84:is kept closed and the valve 85 is opened, so that the aluminum chloridgas may pass up the pipe 83 and be passed back into the condenserelement 34 for condensation purposes, and in its refined state it willbe recharged into the Rodenhauser furnace, as has been described, andthis process may be repeated until the required degree of purity hasbeen attained. At this point the valve 85 is closed and the valve 84 isopened, so that the substantially pure aluminum chlorid may be passedinto what may be termed Condenser #2, as indicated. This condenser is ofthe same structure as the condenser element 34, and the condensedaluminum chlorid in the form of a white powder is brought down into thetank 86. In this tank 86 the aluminum chlorid may be put under pressureby Way of the ipe 87 leading from the compressedair tan 48, and may alsobe subjected to heat from a flame at the burner 69, preferably confinedwithin fire walls. This again meits the aluminum chlorid, which may then70 be conducted to a storage tank 88 through a pipe 89 controlled by avalve 90, the pure aluminum chlorid being heated by a carbon monoxidflame at the burner 68 so as to be kept in a liquid condition.

From this storage tank 38 the liquid aluminum chlorid is conductedthrough a valve 91 and a pipe 92 to the electrolytic vat, which is alsosealed. This liquid condition is maintained by the heat due to theresistance of the bath. The electrolytic vat is illustrated in detail inFigs. 2, 3 and 4 and it will be seen that it comprises a graphite hearth93 and firebrick surrounding walls 9-1, 94:, with magnesite linings 95,95, the entire vat being surrounded by sustaining plates 96. Alongopposite sides of the vat are access openings 97, 97, which are normallysealed by means of covers 98, 98, and a tap hole 99 is provided for apurpose that will be referred to presently, this tap hole being normallyclosed by means of the plug 100. A chlorin exit 101 is provided, and, asindicated in Fig. 1, this exit is connected by means of a pipe 102, inwhich there is a valve 103, with a chlorin compressor 10%, which in turnis connected by a pipe 105 with a chlorin cooler 106, these two elementsbeing merely diagrammatically shown. The cooler 106 is connected bymeans of a pipe 107 with the liquid chlorin tank 31, which has alreadybeen referred to, and the connectlng pipe 107 is provided wvith a valve108.

Returning to the detailed showing of the electrolytic vat. it will beseen from Figs. 3 and i particularly, that the anodes are in the form ofgraphite blocks 109, to each of which three stems 110, 110 are secured,the stems being firmly lodged in a reinforced firebrick seal cover 111.Each of the anodes 110 is provided with a collar 112, which is engagedby a loose collar 113 which may be moved up and down by means of nuts111 on bolt rods 115 extending upwardly from a packing-box cover 116,which surrounds 115 the anode stem and packs it at 117. By thisarrangement the electrode stems may be adjusted vertically so that theproper overall adjustment may be secured Within the vat. Copper bus bar118, 118 connect the 120 tops of the electrode stems 110, and in thisWay the current is conveyed to the bath, the graphite hearth acting asthe opposite elec- 'trode. The center one of each set of three anodestems is drilled axially, as indicated at 110, and this bore isconnected to distributing passageways 120, 120 in the correspondinggraphite block. Each of these bores is connected by means of a pipe 121with the supply pipe 92, which has been hereinbefore referred to, and avalve 122 is disposed in each pipe 121 and is intermittently operatedfor feeding purposes by a traveler 123 which is mounted upon a rotatingshaft 124. Thus, when the various rotating shafts 124 are put intooperation, and, as before stated, the valve 91 is opened to permit thepassage of the liquid aluminum chlorid, a constant feed per unit of timeis afforded down through the passageways 119 and into the vat.

The liquid aluminum chlorid is kept at a high temperature, about 200degrees centigrade, and at about a pressure of two and a halfatmospheres. The heated material from the storage tank is transmittedthrough hot-oil baths in pipes 125 which surround the supply pipes 92,and thus it is insured that the aluminum chlorid be fed into the vat atthe proper temperature. The electrolyte is a bath of melted sodiumchlorid at a high temperature which is primarily induced by externalmeans, but which is maintained by the application of the current, theheat being due to the resistance of the bath. The aluminum chlorid isfed to the bath at such a rate as to keep the bath saturated. The actionwhich takes place in the electrolytic vat separates the aluminum fromthe chlorin and leaves the sodium chlorid. Due to the difference inspecific gravity between the pure aluminum which is thus obtained andthe melted sodium chlorid, it is a simple matter to tap oif the moltenaluminum by removing the plug 100, and in this way the first ultimateobject of my process is obtained-the securing of aluminum in itselemental state from clay. Since the action is secured leaving sodiumchlorid, the electrolyte may go on indefinitely. The chlorin which isfreed is passed to the chlorin compressor 104, then to the cooler andthen to the storage tank, where it is drawn from to sup ly thechloronizmg furnace 9, all as herein efore described.

It will be seen that the process is uniquely continuous, and that thechlorin which is freed in the electrolytimvat may be used over and overagain in the chlorinizing furnace, while the carbon monoxid which 18formed by the oxygen liberated from the clay and the coke which isintroduced is used for burner purposes. It is important that the systembe a closed system, as described, to exclude the moisture and toprotect'the active chlorids, particularly the aluminum chlorid.

An important feature in the matter of the operation of my system isfound in the feeding of the melted aluminum chlorid, or aluminum chloridin powdered condition for that matter, to the electrolytic vat. It is ofimportance that the electrolytic bath is fed with the aluminum chloridin such a way as to keep the bath saturated.

It will be apparent to those skilled in the art that variousmodifications might be made in this system without departing from thespirit or scope thereof. For instance, one might use a differentelectrolyte. In heating the pipes which maintain the aluminum chlorid inits melted condition while being fed to the electrolytic bath, it mightbe better practice in some instances to use electric heating coils thanto use an oil bath, and it might be well to heat the aluminum chloridcontainers in a manner other than by the carbon monoxid flame. With theclosed system whichhas been described, I have the particular advantagethat there is no electrode consumption, and therefore when theelectrodes are adjusted they will remain adj usted, and economic serviceis secured.

Referring to the electrolytic vat, I may mention here that the hearth isthe cathode and the graphite blocks constitute the anode, and I may alsostate that, so faras I have been able to observe, the action of the vatis a reduction process. The aluminum forms globules varying in size frommere specks to considera 1y larger particles, and they occur near thebottom and finally rest upon the bottom. The conclusion from this wouldbe that they are produced by the electrolysis of the sodium chloridbath, and the chlorin is liberated and streams awa with great rapidity.The aluminum which is thus formed is heavier and settles to the bottom,and the particles of aluminum as formed above the bottom frequently jointo form larger particles. As the process continues, the bottom iscovered by drops of aluminum, and, as described, is tapped out from thevat.

It is pertinent here method which has been securing of aluminum rid byelectrolysis, is a plicable in the winning of other metals; or instance,zinc can be secured from zinc chlorid by this process.

While I have already referred to the fact that the broad conception ofmy invention has to do with the winning of any adaptable metal from anyadaptable compound, I de: sire to point out that my process isparticularly useful in the winning of metals from compounds containingthese metals and oxygen and in this respect I have particularly in mindbauxite, which, so far as some of the broader features of m inventionare concerned, would be regard as the equivalent of clay. However, Ihave directed my attention merely to the treatment of clay and the morespecific aspects of my invention will be seen to be directed to thisend.

The various suggestions of changes and the suggestions as toexplanations of the action are presented in closing1 this description,so that those skilled in t e art may be as fully advised as possible,and so that it to suggest that the described, as to the from aluminumchlomay be clear that my invention is to be measured in its broaderaspects as set forth in the broader of the appended claims, and in itsmore limited aspects as set forth in the more specific claims.

I claim as new and desire to secure by Letters Patent:

1. The process of securing a metal from its chlorid which comprisesfeeding the chlorid to a static electrolytic bath of sodium chlorid, andthen independently and simultaneously collecting the. free chlorin andthe metal leaving the electrolytic bath of sodium chlorid.

2. The process of securing aluminum from its chlorid which comprisesfeeding the chlorid to an electrolytic bath continuously, and thenindependently and simultaneously collecting the free chlorin and themetal.

3. The process of breaking up a compound by electrolytic action whichcomprises feeding said compound to an electrolytic bath mechanically ata rate of speed independently calculated to keep the bath saturated.

4. The process of securing aluminum from its chlorid which comprisesmechanically feeding the chlorid to an electrolytic bath at a rate ofspeed calculated to keep the bath saturated.

5. The process of securing aluminum from its chlorid which comprisesfeeding the chlorid to an electrolytic bath of sodium chlorid, thealuminum being maintained in molten condition by the heat due to theresistance of the bat 6. The process of securing aluminum from itschlorid, which comprises mechanically feeding the chlorid to anelectrolytic bath of sodium chlorid at a rate of speed calculated tokeep the bath saturated.

7. The rocess of breaking up a compound by electro ytic action whichcomprises feed ing said compound to an electrolytic bath at a rate ofspeed calculated to keep the bath saturated and by a plurality of pathsto keep the bath uniformly saturated throughout.

8. The process of securing a metal from. its chlori which comprisesmechanically feeding the chlorid to an electrolytic bath at a rate ofspeed calculated to keep the bath saturated.

9. The process of securing aluminum from its 0 lorid which com risesfeeding said chlorid to an electrolytic ath at a rate of speedcalculated to keep the bath saturated and by a plurality of aths to keepthe bath uniformly saturated t rou hout.

10; The process of securing uminum from its chlorid which comprisesmechanically feeding said chlorid to an electrolytic bath at a rate ofspeed calculated to keep the bath saturated and by a plurality of pathsto keep the bath uni ormly saturated throu hout.

he process of breaking up a com- 14. The process of breaking up acompound by electrolytic action which comprises mechanicall feeding saidcompound to an electrolytic bath at a rate of speed independentlycalculated to maintain a definite quantitative relation between the bathand the compound.

15. The process of securing a metal from its chlorid which comprisesmechanically feeding the chlorid to an electrolytic bath at a rate ofspeed independentl calculated to maintain a definite quantitativerelation between the bath and the chlorid.

16. The process of securing aluminum from its chlorid which comprisesmechanically feeding the chlorid to an electrolytic bath at a rate ofspeed independently calculated to maintain a definite quantitative relation between the bath and the chlorid.

17. The process of securing a metal from its chlorid which comprisesmechanically feeding the chlorid to an electrolytic bath of fused sodiumchlorid at a rate of speed independently calculated to maintain adefinite quantitative relation between the bath and the chlorid.

18. The process of securing a metal from a compound by electrolyticaction which comprises mechanically feeding said compound to anelectrolytic bath at a rate of speed independently calculated tomaintain a definite quantitative relation between the bath and thecompound.

19. The process of securing a metal from a compound with a halogen byelectrolyticaction which comprises mechanically feeding said compound toan electrolytic bath at a rate of speed independently calculated tomaintain a definite quantitative relation between the bath and thecompound.

20. The process of securing a metal from its compound with a halogenwhich comprises feeding the compound to an electroic bath continuouslyand then independently and simultaneously collecting the free halogenand the metal.

21. The process of breaking up a compound by electrolytic action whichcomprises feeding said compound to a fused electrolytic bath in definitequantities per unit of time to maintain a definite quantitative relationbetween the bath and the compound, and maintaining the bath in a fusedstate by the heating eifect of the electric current.

22. The process of securing a metal from its chlorid which comprisesmechanically feeding it to an electrolytic bath of the chlorid of ametal more electro-positive than the desired metal at a rate of speedcalculated to maintain the electrolyte so supplied with the lesselectro-positive metal that only that metal will be deposited.

23. The process of breaking up a compound by electrolytic action whichcomprises feedin said compound to an electrolytic bath in definitequantities per unit of time to maintain a definite quantitative relationbetween the bath and the compound.

24. The process of breaking up a compound by electrolytic action whichcomprises controllably feeding said compound to an electrolytic bath indefinite uantities per unit of time to maintain a efinite uantitativerelation between the bath and t e com ound.

25. T e process of breaking u a compound -by electrolytic action WlllCllcomprises mechanically controlling a feed of said compound to anelectrolytic bath in definite quantities per unit of time to main tain adefinite quantitative relation between the bath and the compound.

In witness whereof I hereunto subscribe my name this 7th day of January,A. D. 35

VICTOR M. WEAVER. Witnesses:

G. L. CULLMERRY, J. L. STEWART.

It is hereby certified that in Letters Patent No. 1,297,946, grantedMarch 18,

1919, upon the application of VictOrM. Weaver, of Harrisburg,Penrlsylvania, for an improvement in Processes for Securing Metals fromTheir Compounds," an error appears in the printed specificationrequiring-correction as follows: Page 3, QB 36, for the ord chlorid readchlorin: and that the said Letters Patent should b0 read with thiscorrection therein that the same may conform to the record of the casein the Patent Office.

Signed and sealed this 6th day of May, A. D., 1919.

[SEAL] R. F. WHITEHEAD,

Acting C'omm'iuioner qf Patents.

Correction in Letters Patent No. 1.297.946.

